[emontx] Read the emonTx firmware version (#20619)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

tests/components/emontx/common.yaml

@@ -24,3 +24,9 @@ sensor:
     tag_name: P1
     emontx_id: test_emontx
     unit_of_measurement: W
+
+text_sensor:
+  - platform: emontx
+    emontx_id: test_emontx
+    version:
+      name: emonTx firmware version

tests/components/emontx/text_sensor/__init__.py

@@ -0,0 +1,11 @@
+import esphome.codegen as cg
+from esphome.types import ConfigType
+from tests.testing_helpers import ComponentManifestOverride
+
+
+def override_manifest(manifest: ComponentManifestOverride) -> None:
+    # The platform's own to_code needs a configured hub; only its define is wanted here.
+    async def to_code_testing(config: ConfigType) -> None:
+        cg.add_define("USE_EMONTX_VERSION")
+
+    manifest.to_code = to_code_testing

tests/components/emontx/text_sensor/emontx_version_test.cpp

@@ -0,0 +1,116 @@
+#include <gtest/gtest.h>
+
+#include <string>
+
+#include "esphome/components/emontx/emontx.h"
+#include "esphome/components/text_sensor/text_sensor.h"
+#include "esphome/core/application.h"
+#include "esphome/core/hal.h"
+#include "../common.h"
+
+namespace esphome::emontx::testing {
+
+namespace {
+class EmonTxVersionTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    // The test main does not construct App as generated code does
+    static const bool APP_CONSTRUCTED = (new (&App) Application(), true);
+    (void) APP_CONSTRUCTED;
+    this->sut_.set_uart_parent(&this->uart_);
+    this->sut_.set_version_text_sensor(&this->version_);
+  }
+
+  void TearDown() override {
+    App.scheduler.cancel_timeout(&this->sut_, uint32_t{0});
+    App.scheduler.call(millis());
+  }
+
+  // Lets the delayed 'v' go out
+  static void run_timers() {
+    App.scheduler.call(millis());
+    delay(300);  // NOLINT - test only, the scheduler reads the real clock
+    App.scheduler.call(millis());
+  }
+
+  std::string tx_() const { return std::string(this->uart_.tx.begin(), this->uart_.tx.end()); }
+
+  MockUARTComponent uart_;
+  EmonTx sut_;
+  text_sensor::TextSensor version_;
+};
+}  // namespace
+
+// 'v' must not reach the emonTx in the same burst as the line feed, or it joins the pending command
+TEST_F(EmonTxVersionTest, SetupRequestsVersionAfterDelay) {
+  this->sut_.setup();
+  EXPECT_EQ(this->tx_(), "\n");
+
+  run_timers();
+  EXPECT_EQ(this->tx_(), "\nv\n");
+}
+
+TEST_F(EmonTxVersionTest, SetupUnlocksBeforeRequestingVersion) {
+  this->sut_.set_lock_on_reboot(true);
+  this->sut_.setup();
+  EXPECT_EQ(this->tx_(), "\nemonunlock\n\n");
+
+  run_timers();
+  EXPECT_EQ(this->tx_(), "\nemonunlock\n\nv\n");
+}
+
+TEST_F(EmonTxVersionTest, VersionLinePublished) {
+  this->uart_.push_rx("> Firmware:\r\n  - Bootloader: UART (.bin)\r\n  - Version:    v1.1.1\r\n");
+  this->sut_.loop();
+
+  ASSERT_TRUE(this->version_.has_state());
+  EXPECT_EQ(this->version_.get_state(), "v1.1.1");
+}
+
+TEST_F(EmonTxVersionTest, OtherLinesNotPublished) {
+  this->uart_.push_rx("  - Build:      768be1b (Default)\r\n{\"P1\":100}\r\n  - Version:\r\n  - Version:   \r\n");
+  this->sut_.loop();
+
+  EXPECT_FALSE(this->version_.has_state());
+}
+
+// MSG restarts at 1 after a reboot, e.g. a firmware update
+TEST_F(EmonTxVersionTest, MsgCounterResetRequestsVersion) {
+  this->uart_.push_rx("{\"MSG\":41}\n{\"MSG\":42}\n");
+  this->sut_.loop();
+  EXPECT_TRUE(this->uart_.tx.empty());
+
+  this->uart_.push_rx("{\"MSG\":1}\n");
+  this->sut_.loop();
+  EXPECT_EQ(this->tx_(), "\n");
+
+  run_timers();
+  EXPECT_EQ(this->tx_(), "\nv\n");
+}
+
+// The emonTx may have been flashed during the pause, with MSG already past its old value
+TEST_F(EmonTxVersionTest, ResumeRequestsVersion) {
+  this->sut_.set_paused(true);
+  this->sut_.loop();
+  this->sut_.set_paused(false);
+  this->sut_.loop();
+  EXPECT_EQ(this->tx_(), "\n");
+
+  run_timers();
+  EXPECT_EQ(this->tx_(), "\nv\n");
+}
+
+TEST_F(EmonTxVersionTest, RequestDroppedByPauseSentAgainOnResume) {
+  this->sut_.setup();
+  this->sut_.set_paused(true);
+  this->sut_.loop();
+  run_timers();
+  EXPECT_EQ(this->tx_(), "\n");
+
+  this->sut_.set_paused(false);
+  this->sut_.loop();
+  run_timers();
+  EXPECT_EQ(this->tx_(), "\n\nv\n");
+}
+
+}  // namespace esphome::emontx::testing